The Ministry of Unification has published its statistics on the number of North Koreans who defected to the South in 2013.

According to the statistics, there were 1,516 new arrivals ― almost the same number as 2012. These statistics confirm what has been suspected for the last few years: the North Korean government has been quite successful in its ongoing attempts to curtail defections. The number of new arrivals has nearly halved compared to 2007-10 level.

In the media it is easy to find stories about refugees being shot after being forcibly returned to North Korea from China or being apprehended while trying to cross the Sino-North Korean border. One should be skeptical about such stories, though.

Indeed, studies indicate that around 1995 the North Korean authorities changed their policy toward defections. They began to treat those who were caught in China or on the border with remarkable leniency. In most cases, such people are interrogated (such interrogations often include torture) and then are sent to a prison camp for a short imprisonment (usually for a couple of months).

This approach was introduced at the time when the number of refugees began to grow dramatically. The collapse of North Korea's food supply in the mid-1990s provoked a massive exodus of North Koreans to China, and up to 200,000 North Koreans were living there at certain points in the late 1990s.

Facing such a massive exodus, the government of Kim Jong-il quietly began to ignore earlier regulations ― these regulations would have meant that apprehended refugees would have gone to concentration camps for long terms. Under Kim Jong-il, the authorities only heavily punished those refugees who had been found to have spent much time interacting with dubious non-Chinese foreigners and/or missionaries.

This relaxation might reflect the relative softness of Kim Jong-Il, but was largely driven by pragmatic considerations. When the northern provinces were devastated by famine, it was of little harm to the regime if the most active and restless (and potentially, therefore, most dangerous) people were tacitly allowed to leave the country in search of food and jobs. In other words, defection became a safety valve and this was well understood in Pyongyang.

It was also significant that most of such refugees, being poorly educated farmers and manual workers from the countryside, did not become involved in political activities upon their arrival to South Korea. While there are some 25,000 refugees in South Korea, most of these people are busy making ends meets.

So, the late Kim Jong-il might have thought that he did not face much in the way of risk by turning a blind eye to the massive (technically illegal) migration of his subjects. His son Kim Jong-un, however, seems to have a very different opinion on the subject.

As soon as Kim Jong-un was made heir apparent to his father in 2010, the North Korean authorities suddenly changed their approach to defection. In 2010-13, there was a massive build-up in security on the Sino-North Korean border. The number of troops increased and troops were rotated frequently to make it more difficult for military personnel to form local connections, corrupt or otherwise.

Significantly, the North Korean government media began to wage a campaign against defection. They have featured some former refugees disappointed enough with life in South Korea to return to North Korea. These people told the North Korean audience of how awful the capitalist South is. This marks a sea change in policy, since the issue of defection has hitherto been strenuously avoided by the North Korean media.

As statistics testify, the policy has seemingly worked. The number of defections has decreased considerably, from 2,929 in 2009 to 1,516 in the last year. The combination of fear and persuasion, combined with palpable economic improvements at home, has seemingly borne fruit for the regime.

We do not know for sure why did Kim Jong -un change the regime's attitude toward refugees, but we can make some educated guesses. To start, the North Korean authorities no longer need the safety valve: the domestic economy is doing better.

At the same time, refugees are dangerous even when they are not politicized, because most of them keep in contact with their relatives in the North ― and relate the stories of South Korea's material prosperity and individual freedom. In order to maintain connections so, they use brokers in China (who easily smuggle both letters and money) as well as Chinese mobile phones.

It seems that Kim Jong-un understands the threats associated with information about South Korean prosperity. Therefore, the young Kim is doing what he can to check this dangerous trend, and has seemingly succeeded thus far.

Professor Andrei Lankov was born in St. Petersburg, Russia, and now teaches at Kookmin University in Seoul. You can reach him at anlankov@yahoo.com.